Buzzzz

[strummer]

I am pretty sure your bass has a "bullet" nut at the headstock end, right? Then you do not have to remove the neck, unless straightening it involves clamping.
First remove the bullet, then remove the strings and put the bullet back after lubricting the truss rod threads. Tighten the rod until neck is straight, put the strings on one at a time and check relief. Adjust bullet when necessary.
If you can not adjust the neck enough, I *think* the old MMs are just like f*nde*s, and you have reached the end of the threaded part of the rod. Then you might try a shim between the wood and the bullet. This sometimes works.

The rod in your bass sits in a curved channel, and the end not visible is fixed. Midway between the ends of the fretboard, the rod is it's farthest from the fretboard.

 

[Rod Trussbroken]

>>>>My old (1980) Stingray hasn'r t got a "wheel" it has an allen key thingy up at the headstock end.Am I right in assuming that the "wheel" is down at the heel end of the neck ?? if so, I am supposing that "turning the wheel clockwise" equates to tightening, and hence turning the old arrangement anti-clockwise does the same thing. Does anyone have an understandable description of the neck/rod arangement in an old Fender SR4 Fretless ?

The capstan truss wheel is located at the heel of the neck (down near the pickups). Looking from the heel of the neck, in the direction of the headstock, the wheel is turned clockwise to make the neck flatter. The bullet-type trussnut is located at the top of the neck, at the headstock, like your Bass. Looking from the headstock, down towards the pickup, it is also adjusted clockwise to make the neck flatter.

>>>....and now the rod adjustment seems to have become extremely stiff. Can anyone recommend some form of easing fluid to free it. I guess II need to remove the neck to do it .. yes? Has anyone done it and can help ??

This is the way I go about it:

The neck doesn't have to be removed. Try and remove the bullet trussnut by turning it anti-clockwise (as you look from the headstock down towards the pickup). It should screw right out. If you find it difficult to remove, take it to a luthier! If you can remove it, put a little lubricant on the bullet trussnut threads. Try not to get the lubricant on the wood where the nut fits into the neck. I use a silicon based lubricant (as opposed to petroleum) in the form of a gel. It can be applied to the threads (inside the nut) with a match stick. The gel prevents the lubricant from running everywhere. When adjusting a bullet truss, loosen the strings first and retune to pitch before re-assessing the degree of adjustment.

>>>With it as tight as I dare to go, there's still a slight bow to the neck, and if I drop the strings to accommodate a light touch, they buzz around the 6th to the 10th "fret" (its fretless but you know what I mean). I can adjust out the buzz with the bridge, but I would like to try a flat fingerboard.

If you feel excessive resistance on the nut and, at the same time, the neck still isn't flat, then you've gone to the limit of truss adjustment. Don't go any further because you'll break the truss rod. Some necks wont adjust perfectly straight on the Pre-EB Basses (mine wont either). If the strings buzz from the 6th fret "position" up to the heel, then you have to raise the string saddles on the bridge. The truss adjustment only affects buzz only from the 6th fret down to the nut. If you have no buzz in that area, then trying to flatten the neck further takes the matter nowhere.

My way of doing it is to get the neck as straight as you can. Then adjust string height so there's no buzz from the 5th or 6th fret up towards the heel. After doing that, and the strings buzz from the 6th fret down to the nut, then you add relief by turning the bullet truss anti-clockwise (looking from headstock in the direction of the pickup). Some necks wont adjust perfectly straight. If you don't have buzz from the 6th to the nut, then there's no problem to begin with.

>>>Do I have a major problem? if not, can I ease the neck and rod myself? should it really be flat or is a little bow acceptable ?

I don't think you have a major problem. All necks must have a little bow as the strings vibrate in an eliptical pattern.

Just a reminder...if you feel any excessive resistance while adjusting the truss (in either direction), then give it to a luthier as you could easily break the truss or strip the threads on the trussnut.

You may get a lower action by having the fretboard shaved by your luthier.

 

[radiotrib]

Brilliant !!! ... I'm just leaving it to settle down for an hour or so before retuning and testing .. but it looks like your advice was ecactly what I needed and it gave me the confidence to try it out ....

The rod was in need of lubrication. Done that, and refitted the little bullet, adjusted as I restrung, and now the neck is pretty near flat with just a soft curve to the last 4-5 frets at the head end.The action is lower han it's been for years, and clean (fartless as well as fretless).

IMO - just perfect,

Yet again, thanks for all the invaluable support you guys give.